Boiler Room in a Box

Plumdog_2

I ran across that once; it was intended to use a Takagi tankless water heater for both domestic and space heat, hence the 0011 pumps to try and get enough flow through the little tankless to trick it into producing heat. Homeowner bought it for do-it-ur-self heat project. He had a lot of trouble with it. Now in foreclosure.

Paul Fredricks_9

BRIAB

Went to a customers house today. They had a system installed with a Boiler Room in a Box. These are pre-made boards with all the components. The theory is you just have to hook it to a boiler and the radiation home runs.

There is a plate heat exchanger that makes the domestic hot water. A flow switch detects a call for water and the main circulator kicks in. The boiler side of the coil is in series with the boiler supply so when any of the zones call the heat exchanger gets heat. The customer says he gets plenty of hot water.

The baseboard loops are not extremely long and they are 3/4", but they're using 0011's on each one. Seems like overkill? The bigger problem is the zones are getting heat in the summer, he has to keep the ball valves closed so the heat doesn't gravity. They used swing checks instead of flow checks so that may be a big part of the problem. There's also a relief valve piped into the bottom of the air separator, but there's one on the boiler too. ???

This seems like a strange way of doing things to me, but maybe you guys have other ideas. To top it all off, the installer used the longest Riello tube I've seen, and piped the return so that you can't open the swing door.

Brad White_198

Maybe that long burner tube allows

the customer gets a better cost of oil when the burner itself is in the next county?

011's for baseboard loops? If 3.0 GPM, that would work against 27 feet of head... maybe the baseboard is also in the next county....

I can see if a small-tube radiant circuit but not baseboard where a 005 or 006 would be fine.

Nice concept if it worked, but I am glad you are on the case.

Paul Fredricks_9

Just not 100% sure where to go from here. I know that 2 of the swing checks are hung up, so we'll change those to flow checks. What I'd really like to do is rip the circs out and go with zone valves. It's easy to really get going on lots here, but I'm trying to keep the costs down for the customer.

I did ask if he had a lot of noise in the pipes when the circulators run and he said no. I was thinking there would be a lot of velocity noise.

Big Ed_4

Check the piping

Trying to figure out the piping set up from your photos. This system shoud be piped primary secondary with the heat exchaner on the primary. But you mentioned it is piped in series ?

Brad White_198

I would think that

a single 011 would do the house... and leave a few spares too~

Flow checks, yes. Zone valves, yes again. Even if no noise, the electric bill has to show some movement.

Paul Fredricks_9

After I looked at it more, it is set up primary/secondary. It's a little hard to see in the pictures. But I get the feeling that the only time the secondary circ kicks in is on a call for hot water (flow), but I could be wrong about that. Think I'm going to have to take another look.

Paul Fredricks_9

Electric Bill

Yeah, that's true. We'll see how far he wants to go.

Any ideas on electrical savings? I know a zone valved system would far less than the current set up, but are we talking slashing $4 a month off the electric bill, or $40?

Big Ed_4

I would think there would also be a ensaficant heat problem . Unless there is 12 daughers living in the home . Just thinking for you.

Paul Fredricks_9

I think his only problem has been over heating. That secondary circ must kick in on a call for heat. We'll see.

Brad White_198

A Taco 011

draws 1.76 Amps by the nameplate and at 115 volts that is 202 Watts per circulator.

Every five of those draws about 1.0 kWH so would cost your electric rate per hour to run. What, 10 cents, 15? 20? If the circulators run constantly, that is between $2.40 and $4.80 per day. If intermittent, naturally that is proportionately less.

Not that this is a huge thing in itself but over time. One also has to consider that a Grundfos 15-58 might do the same duty for about 85 Watts for the entire house, a Wilo Stratos Eco or Grundfos Alpha, even less when control valves are used.

Say it is 85 Watts, call it 100, that is half of one 011 and might cost you a kWH over ten hours of operation, not one. A day would cost you between 24 and 48 cents, that is some change back per hour.

Put in a Stratos Eco or Alpha and with zone valves imposing a delta-P, your Cube-Root function comes into play. Your Wattage could drop to under ten at low loads.

Any such change-out has to be mindful of an economic payback of course. If you remove the circulators and install control valves at $75 a pop plus your time, you would be have to justify it over a reasonable timeframe. But at least you have a point of reference into which to plug your numbers.

Some HO's will go with it for altruistic reasons, or to rid themselves of the annoying drip-drip-drip of their electric meter leaking.

I would at least lay out the numbers so they see. If anything else, they will see how darned good you are and how it should have been done in the first place!

Paul Fredricks_9

Thanks Brad

I can always count on you to do the thinking for me. I think we are the highest electric in the country now, like $.22

Zone valves, plus repiping, plus rewiring. It won't be cheap, but he might just like the idea.

Thanks again.